Losing ssh connection during apt upgrade

[Bo Berglund]

On Fri, 29 Jan 2021 15:05:27 +0000, Chris Green <cl at isbd.net> wrote:

>I've done 'do-release-upgrade' via ssh.  It does warn you that it's
>possibly not a good idea but it also tells you that it sets up a
>secondary ssh in case the first one dies for some reason.
>
>Just doing upgrade and full-upgrade via ssh is pretty low risk I
>think, if it falls over you just re-connect and carry on.  I find apt
>is pretty bomb-proof and even suggests ways to mend things if they do
>fall over for any reason.
>

FWIW:

A few years back I did a do-release-upgrade operation on an ubuntu server 16.04
LTS via ssh if I remember correctly.

As the processing was pretty time consuming I did not sit at the console all the
time and when I returned after some hour or so I was greeted by a black screen
with nothing I could do to return it to working operation.
I let it sit for a couple of hours and then pulled the power on it to let it
reboot, this time after attaching a keyboard and monitor to it.

It did boot OK so nothing was damaged but I had to investigate the cause of the
blackout since I had another similar box in need of going from 16 to 18.
And it is sitting across the world with only ssh access from my location.

What I found is that there is a default setting for a "screensaver" for the
console which kicked in and blanked the screen and then it was not possible to
get it back....

So now I always make sure that the console screensaver is *disabled permanently*
on my headless server ubuntu boxes.


-- 
Bo Berglund
Developer in Sweden